An embryo is a developing human during the early stage of prenatal development, from implantation through approximately the end of the eighth week after fertilization.
The embryonic period is characterized by rapid development and organization of the body’s major structures and organ systems. It is a particularly important period for structural development.
After the embryonic period, the developing human is generally referred to as a fetus until birth.
COMMONLY CONFUSED WITH
- Fetus: the developmental stage following the embryonic period.
- Zygote: the single cell formed when an egg and sperm fuse, before the embryo develops.
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